I’m happy to see someone else caring as much as I do about the look of planets.
Might I suggest making Naboo go through seasons? In TPM it’s summer, representing the Republic standing strong. In AotC it’s fall, representing the slowly crumbling Republic. In RotS, it’s a snowy winter, representing the dissolution of the Republic. This also evenly spreads the workload, since TPM, which features Naboo prominently, wouldn’t need to be altered at all, while the hardest edit to pull off (adding snow) would be relegated to a movie that only features one brief scene on Naboo.
idea from a DeviantArt user named Andres
Without a link and with such a generic name it’s impossible to find the picture(s) you’re referring to.
I’m not sure why you wanna change Alderaan though. It’s fine the way it is, and its appearance is so brief.